See-through computer display systems with vision correction and increased content density

ABSTRACT

Provided herein are examples of an impact resistant glass-waveguide configuration for a see-through head-worn computer display. In embodiments, the configuration includes vision correction and content density control through electrochromic and/or photochromic systems.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application No. 62/661,720, filed Apr. 24, 2018, thecontents of which are incorporated by reference herein in theirentirety.

BACKGROUND Field of the Invention

This invention relates to see-through computer display systems withvision correction and/or increased content density.

Description of Related Art

Head mounted displays (HMDs) and particularly HMDs that provide asee-through view of the environment are valuable instruments. Thepresentation of content in the see-through display can be a complicatedoperation when attempting to ensure that the user experience isoptimized. Improved systems and methods for presenting content in thesee-through display can improve the user experience.

SUMMARY

Aspects of the present invention relate to methods and systems for thesee-through computer display systems with waveguides that include avision corrective and increased content density by reducing scene light.

These and other systems, methods, objects, features, and advantages ofthe present invention will be apparent to those skilled in the art fromthe following detailed description of the preferred embodiment and thedrawings. All documents mentioned herein are hereby incorporated intheir entirety by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are described with reference to the following Figures. Thesame numbers may be used throughout to reference like features andcomponents that are shown in the Figures:

FIG. 1 illustrates a head-worn computer ecosystem in accordance with theprinciples of the present invention.

FIG. 2 illustrates a head worn computing system with optical system inaccordance with the principles of the present invention.

FIG. 3 illustrates an exemplary image transfer module in accordance withthe principles of the present invention.

FIG. 4 illustrates a waveguide construction with vision correction andincreased content density through controlled scene light transmission inaccordance with the principles of the present invention.

While the invention has been described in connection with certainpreferred embodiments, other embodiments would be understood by one ofordinary skill in the art and are encompassed herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Aspects of the present invention relate to head-worn computing (“HWC”)systems. HWC involves, in some instances, a system that mimics theappearance of head-worn glasses or sunglasses. The glasses may be afully developed computing platform, such as including computer displayspresented in each of the lenses of the glasses to the eyes of the user.In embodiments, the lenses and displays may be configured to allow aperson wearing the glasses to see the environment through the lenseswhile also seeing, simultaneously, digital imagery, which forms anoverlaid image that is perceived by the person as a digitally augmentedimage of the environment, or augmented reality (“AR”).

HWC involves more than just placing a computing system on a person'shead. The system may need to be designed as a lightweight, compact andfully functional computer display, such as wherein the computer displayincludes a high resolution digital display that provides a high level ofemersion comprised of the displayed digital content and the see-throughview of the environmental surroundings. User interfaces and controlsystems suited to the HWC device may be required that are unlike thoseused for a more conventional computer such as a laptop. For the HWC andassociated systems to be most effective, the glasses may be equippedwith sensors to determine environmental conditions, geographic location,relative positioning to other points of interest, objects identified byimaging and movement by the user or other users in a connected group,and the like. The HWC may then change the mode of operation to match theconditions, location, positioning, movements, and the like, in a methodgenerally referred to as a contextually aware HWC. The glasses also mayneed to be connected, wirelessly or otherwise, to other systems eitherlocally or through a network. Controlling the glasses may be achievedthrough the use of an external device, automatically throughcontextually gathered information, through user gestures captured by theglasses sensors, and the like. Each technique may be further refineddepending on the software application being used in the glasses. Theglasses may further be used to control or coordinate with externaldevices that are associated with the glasses.

Referring to FIG. 1, an overview of the HWC system 100 is presented. Asshown, the HWC system 100 comprises a HWC 102, which in this instance isconfigured as glasses to be worn on the head with sensors such that theHWC 102 is aware of the objects and conditions in the environment 114.In this instance, the HWC 102 also receives and interprets controlinputs such as gestures and movements 116. The HWC 102 may communicatewith external user interfaces 104. The external user interfaces 104 mayprovide a physical user interface to take control instructions from auser of the HWC 102 and the external user interfaces 104 and the HWC 102may communicate bi-directionally to affect the user's command andprovide feedback to the external device 108. The HWC 102 may alsocommunicate bi-directionally with externally controlled or coordinatedlocal devices 108. For example, an external user interface 104 may beused in connection with the HWC 102 to control an externally controlledor coordinated local device 108. The externally controlled orcoordinated local device 108 may provide feedback to the HWC 102 and acustomized GUI may be presented in the HWC 102 based on the type ofdevice or specifically identified device 108. The HWC 102 may alsointeract with remote devices and information sources 112 through anetwork connection 110. Again, the external user interface 104 may beused in connection with the HWC 102 to control or otherwise interactwith any of the remote devices 108 and information sources 112 in asimilar way as when the external user interfaces 104 are used to controlor otherwise interact with the externally controlled or coordinatedlocal devices 108. Similarly, HWC 102 may interpret gestures 116 (e.g.captured from forward, downward, upward, rearward facing sensors such ascamera(s), range finders, IR sensors, etc.) or environmental conditionssensed in the environment 114 to control either local or remote devices108 or 112.

We will now describe each of the main elements depicted on FIG. 1 inmore detail; however, these descriptions are intended to provide generalguidance and should not be construed as limiting. Additional descriptionof each element may also be further described herein.

The HWC 102 is a computing platform intended to be worn on a person'shead. The HWC 102 may take many different forms to fit many differentfunctional requirements. In some situations, the HWC 102 will bedesigned in the form of conventional glasses. The glasses may or may nothave active computer graphics displays. In situations where the HWC 102has integrated computer displays the displays may be configured assee-through displays such that the digital imagery can be overlaid withrespect to the user's view of the environment 114. There are a number ofsee-through optical designs that may be used, including ones that have areflective display (e.g. LCoS, DLP), emissive displays (e.g. OLED,micro-LED), holographic surfaces, TIR waveguides, and the like. Inembodiments, lighting systems used in connection with the display opticsmay be solid state lighting systems, such as LED, OLED, quantum dot,quantum dot LED, etc. In addition, the optical configuration may bemonocular or binocular. It may also include vision corrective opticalcomponents. In other embodiments, the HWC 102 may be in the form of ahelmet with a see-through shield, sunglasses, safety glasses, goggles, amask, fire helmet with see-through shield, police helmet with seethrough shield, military helmet with see-through shield, utility formcustomized to a certain work task (e.g. inventory control, logistics,repair, maintenance, etc.), and the like.

The HWC 102 may also have a number of integrated computing facilities,such as an integrated processor, integrated power management,communication structures (e.g. cell net, WiFi, Bluetooth, local areaconnections, mesh connections, remote connections (e.g. client server,etc.)), and the like. The HWC 102 may also have a number of positionalawareness sensors, such as GPS, electronic compass, altimeter, tiltsensor, IMU, and the like. It may also have other sensors such as acamera, rangefinder, hyper-spectral camera, Geiger counter, microphone,spectral illumination detector, temperature sensor, chemical sensor,biologic sensor, moisture sensor, ultrasonic sensor, and the like.

The HWC 102 may also have integrated control technologies. Theintegrated control technologies may be contextual based control, passivecontrol, active control, user control, and the like. For example, theHWC 102 may have an integrated sensor (e.g. camera) that captures userhand or body gestures 116 such that the integrated processing system caninterpret the gestures and generate control commands for the HWC 102. Inanother example, the HWC 102 may have sensors that detect movement (e.g.a nod, head shake, and the like) including accelerometers, gyros andother inertial measurements, where the integrated processor mayinterpret the movement and generate a control command in response. TheHWC 102 may also automatically control itself based on measured orperceived environmental conditions. For example, if it is bright in theenvironment the HWC 102 may increase the brightness or contrast of thedisplayed image. In embodiments, the integrated control technologies maybe mounted on the HWC 102 such that a user can interact with itdirectly. For example, the HWC 102 may have a button(s), touchcapacitive interface, and the like.

As described herein, the HWC 102 may be in communication with externaluser interfaces 104. The external user interfaces may come in manydifferent forms. For example, a cell phone screen may be adapted to takeuser input for control of an aspect of the HWC 102. The external userinterface may be a dedicated UI, such as a keyboard, touch surface,button(s), joy stick, and the like. In embodiments, the externalcontroller may be integrated into another device such as a ring, watch,bike, car, and the like. In each case, the external user interface 104may include sensors (e.g. IMU, accelerometers, compass, altimeter, andthe like) to provide additional input for controlling the HWD 104.

As described herein, the HWC 102 may control or coordinate with otherlocal devices 108. The external devices 108 may be an audio device,visual device, vehicle, cell phone, computer, and the like. Forinstance, the local external device 108 may be another HWC 102, whereinformation may then be exchanged between the separate HWCs 108.

Similar to the way the HWC 102 may control or coordinate with localdevices 106, the HWC 102 may control or coordinate with remote devices112, such as the HWC 102 communicating with the remote devices 112through a network 110. Again, the form of the remote device 112 may havemany forms. Included in these forms is another HWC 102. For example,each HWC 102 may communicate its GPS position such that all the HWCs 102know where all of HWC 102 are located.

FIG. 2 illustrates a HWC 102 with an optical system that includes animage production module 202 and an image transfer optical module 204.While the modules 202 and 204 will generally be described as separatemodules, it should be understood that this is illustrative only and thepresent invention includes other physical configurations, such as thatwhen the two modules are combined into a single module or where theelements making up the two modules are configured into more than twomodules. In embodiments, the image production module 202 includes acomputer controlled display (e.g. LCoS, DLP, OLED, micro-LED etc.) andbe arranged to transmit or project image light to the image transferoptical module 204. In embodiments, the image transfer optical module204 includes eye delivery optics that are configured to receive theimage light and deliver the image light to the eye of a wearer of theHWC. The transfer optical module may include reflective, refractive,holographic, TIR, etc. surfaces. It should be noted that while theoptical modules 202 and 204 are illustrated in one side of the HWC suchthat image light can be delivered to one eye of the wearer, that it isenvisioned by the present invention that embodiments will contain twoimage light delivery systems, one for each eye. It should also be notedthat while the image production module 202 is depicted in FIG. 2 asabove the image transfer module 204, the inventors envision otherconfigurations as well. The image may be projected to the image transfermodule 204 from the top, bottom side, at a corner, from behind, from thefront, etc. These configurations may depend on what optics are includedin the module.

FIG. 3 illustrates a specific type of image transfer module 204. Itillustrates a waveguide with image light direction surfaces 302 todirect the image light within the waveguide. There are a number ofdifferent types of waveguides with image light direction surfaces:holographic, single layer holographic, multi-layer holographic, thickfilm holographic, outer surface holographic, prism, surface relief,active holographic, etc. Reference, which is incorporated herein, ismade to https://uploadvr.com/waveguides-smartglasses/ to provide someexamples of waveguides with direction surfaces. In the exampleillustrated in FIG. 3, an image production module 202 projects lightinto an area of the waveguide 302 that includes an input surface 304adapted to re-direct the image light internally, through total internalreflection (TIR), to a fold surface 308 that redirects the image lightwithin the waveguide 302 to an output surface 310 that is adapted tore-direct the light out of the waveguide 302 towards a user's eye. Theinput surface and output surface, in embodiments, are further designedto expand the image light such that, once redirected out of thewaveguide 302, it forms a large field of view for the user. Each of thesurfaces 304, 308 and 310 may be prisms, holographic, active, passive,many layered, single layered, internal to the waveguide, external to thewaveguide, etc. The example provided in FIG. 3 is merely exemplary innature to help the reader understand that there are various types ofwaveguides with directional surfaces to manage the image light. Furtherto that point, while the illustrated configuration shows a particulararrangement and orientation of the image production module, thewaveguide and the various surfaces, it should be understood that theinventors envision that there are other configurations that work and theconfiguration generally depends on the finished product's requirements.

FIG. 4 illustrates a waveguide construction with vision correction andincreased content density through controlled scene light transmission inaccordance with the principles of the present invention. The inventorsdiscovered that waveguides, while useful and a very good form factor forsmart-glasses, are fragile because they are made of glass. They are alsoexpensive, so breaking them in a pair of glasses is not good. Inaddition, because they are glass, any breakage could result in an eyeinjury for the user. The embodiment illustrated in FIG. 4 hardens thewaveguide such that it is less susceptible to breakage and/or impacts.In addition, the embodiment in FIG. 4 provides a waveguide see-throughaugmented reality solution with a corrective vision element andincreased content density due to the controlling of scene lighting thatprovides back lighting to content provided through the waveguide.

The waveguide 302 of FIG. 4 is part of an assembly once the othercomponents in the illustration are added. As illustrated, the severalcomponents stack together to form, at least a portion of, an example ofan image transfer module 204. The stack includes the waveguide 302 withan inner protective layer (e.g. polycarbonate, protective plate, etc.)402, which is on the user's eye 414 side of the stack. The stack alsoincludes an outer protective layer (e.g. polycarbonate, protectiveplate, etc.) 404 on the opposite side of the waveguide 302. Inembodiments, an air gap 412 is maintained on each side of the waveguide302 such that the waveguide operates properly. That is, the stacking ofoptical elements includes an air gap on both sides of the waveguide suchthat the total internal reflection nature of the reflections inside ofthe waveguide are not disrupted. The air gap 412 preserves thesubstantial index of refraction difference between the materialwaveguide 302 and the transition to the next material.

The optical stack of FIG. 4 further includes a vision correction optic410 (e.g. a molded elastomeric that sticks to the inner protective layer402 through surface adhesion, a glass or plastic vision correction opticthat is adhered to the protective inner layer 402, etc.) The visioncorrection optic is meant to correct the user's vision in the same wayas other prescription lenses, but in this embodiment, it is placed onthe inner protective layer 402 so it will correct the user's view of notonly the surrounding environment but also the content presented throughthe waveguide 302. In embodiments, the vision corrective optic 410 is amolded elastomeric that sticks to the inner protective layer 402 throughsurface adhesion. This allows for quick and easy application of a visioncorrection optic 410 that is made specifically for the user. Anophthalmologist, or other prescriber of corrective lenses, could makeand sell correctives that could then be applied by the user byessentially sticking the optic onto an outside surface of the innerprotective layer 402. Of course, in situations where a prescriber is notrequired, the user may simply purchase a corrective and apply it to theinner protective layer 402 (e.g. a ‘reader’ optic for increasedmagnification). In embodiments, it is important to have a vertical andplanar waveguide 302 and/or vertical and planar (e.g. planar at leastover the surface where the vision corrective optic 410 is to be mounted)inner protective layer 402 positioned in front of the user's eye for thevision corrective optic 410 to work properly. When the waveguide 302 ispositioned substantially vertically, image light transmits from thewaveguide at substantially 90 degrees from the waveguide surface towardsthe user's eye. This is because typical vision corrective optics 410 areoptically designed to be looked through when they are positionedvertically. This avoids needing to make a very complicated prescriptionon the vision correction optic 410 to compensate for the angle throughwhich the user would be viewing. In an alternate embodiment, if thewaveguide 302 is on an angle off of vertical, the inner protective layer402 may include an angle on it's outer surface (i.e. closest to the eye414) or be mounted on an angle with respect to the waveguide 302 suchthat when the vision corrective optic is attached, it is vertical withrespect to the user's eye 414. In embodiments, the inner protectivelayer 402 may include one or more markings, or a template may beprovided, to help a user with the alignment of the vision correctionoptic 410.

In embodiments, the inner protective layer 402 may itself include avision corrective portion. The inner protective layer could be formedout of polycarbonate, or other suitable material, and shaped into thecorrective prescription for the user. Then the vision corrected innerprotective layer could be attached to the waveguide 302 such that theair gap 412 is preserved. This would eliminate the need for a separatematerial to be applied to the inner protective layer 402. Of course,this configuration may require a more involved manufacturing or userprocess for installing the vision corrected inner protective layer 402.

As illustrated in FIG. 4, in embodiments, the stack may include an outerprotective layer 404 that is positioned to provide an air gap 412between the outer protective layer 404 and the waveguide 302 to preservethe proper total internal reflections of the waveguide when it isdelivering computer content to the user's eye in a head-mountedsee-through computer display. The stack may also include anelectrochromic layer 408 that may be controlled by a processor in thehead-worn computer 102. The electrochromic layer may be computercontrolled to quickly reduce or increase the amount of scene lightreaching the waveguide 302. The scene light essentially forms backgroundlight for the computer images presented in the waveguide 302 because ofthe see-through nature of the waveguide 302. With high transmissivity onthe outside of the waveguide 302 (i.e. the opposite side of the user'seye) computer content presented in the waveguide 302 may be transparentand/or require a high brightness for the content to overcome the scenelight. With the electrochromic layer 408 activated to provide dimming ofthe scene light, the computer content may be less transparent and/or thebrightness of the content may be reduced because there is not as muchscene light to overcome. In embodiments, the electrochromic layer 408 isapplied directly to the outer protective layer 404. In otherembodiments, the electrochromic layer 408 is applied to an intermediatelayer.

The inventors discovered that when applying electrochromic surfaces toglasses formats, there are significant difficulties. The electrochromicsurface tends to not apply well to complicated shapes, includingcompound radiuses like a standard corrective glass lens or sunglasslens. It becomes somewhat easier to apply the surface to a single curvein a surface. It is easiest and produces the best results when it isapplied to a flat planar surface. In embodiments, the air gap designdescribed herein may be used in connection with any shapedelectrochromic surface.

In embodiments, the outer protective layer 404 may include photochromicmaterial(s). This would provide auto-dimming of the scene light based onthe intensity of the scene light. A photochromic layer may be providedin a separate layer on either side of the outer protective layer.Typically, the photochromic layer would be positioned further from theuser's eye than the electrochromic layer such that the electrochromiclayer did not have an effect of the performance of the photochromiclayer.

In embodiments, anti-reflective coatings may be applied to any or all ofthe optical stack's surfaces illustrated in connection with FIG. 4 thatare exposed to air in the final assembly to prevent reflections duringuse of the head-worn computer 102 to prevent distracting reflections.

In embodiments, inner and outer protective layer 402 and 408 may beapplied to the waveguide 302 without leaving the air gaps 412 by using amaterial for the protective layers that substantially matches the indexof refraction of the material used for the waveguide 302. By using anindex matching material, the total internal reflection of the waveguidemay use the outer surfaces of the protective layers. In such aconfiguration, an air gap may be provided between the inner protectivelayer 402 and the corrective optic 410. Further, in such a configurationan air gap may be provided between the outer protective layer 404 andthe electrochromic layer 408.

In embodiments, the waveguide 302, or portions thereof, may be made ofchemically treated glass to increase the waveguides strength (e.g.Gorilla Glass).

In an embodiment, a head-worn see-through computer display, may includea glass waveguide having a first inner surface, the first inner surfacehaving a planar area at least in a region where image light is projectedfrom the glass waveguide towards an eye of a user, the glass waveguidefurther configured such that image light transmits from it atapproximately 90 degrees as referenced to the first inner surface, aprotective inner layer positioned between the glass waveguide and theeye of the user, wherein the protective inner layer is furtherpositioned to provide a first air gap between the glass waveguide andthe protective inner layer, and a vision corrective optic mounted on theprotective inner layer and positioned between the protective inner layerand the eye of the user. The glass waveguide may include at least oneholographic surface. The at least one holographic surface includes aplurality of holographic surfaces. The glass waveguide may be positionedvertically in front of the eye of the user. The protective inner layermay have an outer surface upon which the vision corrective optic ismounted and the outer surface may be positioned vertically in front ofthe eye of the user. The head-worn see-through computer display mayfurther include a protective outer layer positioned on a waveguide sideopposite the protective inner layer, wherein the protective outer layermay be further positioned to provide a second air gap between theprotective outer layer and the glass waveguide. The head-wornsee-through computer display may further include an electrochromicsurface controlled by a processor to controllably block at least aportion of scene light from reaching the glass waveguide. Theelectrochromic surface may be positioned between the protective outerlayer and the glass waveguide. The electrochromic surface may be appliedto the protective outer layer and the second air gap may be between theelectrochromic surface and the glass waveguide. The protective outerlayer may be photochromic. The vision corrective optic may include anelastomeric optic that attaches to the protective inner layer withsurface tension.

Although embodiments of HWC have been described in language specific tofeatures, systems, computer processes and/or methods, the appendedclaims are not necessarily limited to the specific features, systems,computer processes and/or methods described. Rather, the specificfeatures, systems, computer processes and/or and methods are disclosedas non-limited example implementations of HWC. All documents referencedherein are hereby incorporated by reference.

What is claimed is:
 1. An optical stack comprising: a waveguide; a firstprotective layer disposed on a first side of the waveguide; a secondprotective layer disposed on a second side of the waveguide; a visioncorrective optic disposed on the first side of the waveguide; and anelectrochromic layer disposed on the second side of the waveguide. 2.The optical stack of claim 1, wherein the first protective layercomprises polycarbonate.
 3. The optical stack of claim 1, wherein thefirst protective layer comprises a protective plate.
 4. The opticalstack of claim 1, wherein the vision corrective optic is disposedbetween an eye of a user and the first protective layer.
 5. The opticalstack of claim 1, wherein the vision corrective optic comprises anelastomeric.
 6. The optical stack of claim 1, wherein the visioncorrective optic is coupled to the first protective layer via surfaceadhesion.
 7. The optical stack of claim 1, wherein the first protectivelayer comprises the vision corrective optic.
 8. The optical stack ofclaim 1, further comprising: a first air gap disposed between thewaveguide and the first protective layer; and a second air gap disposedbetween the waveguide and the second protective layer.
 9. The opticalstack of claim 1, wherein the electrochromic layer is disposed betweenthe waveguide and the second protective layer.
 10. The optical stack ofclaim 9, wherein the electrochromic layer is coupled directly to thesecond protective layer.
 11. The optical stack of claim 9, furthercomprising a substrate layer disposed between the electrochromic layerand the second protective layer, wherein the electrochromic layer iscoupled directly to the substrate layer.
 12. The optical stack of claim1, wherein the waveguide, the first protective layer, and the secondprotective layer have substantially the same refractive index.
 13. Theoptical stack of claim 1, wherein the waveguide comprises a holographicsurface.
 14. The optical stack of claim 1, wherein: the optical stack isconfigured to present image light and scene light to a user, a source ofthe scene light is disposed on the second side of the waveguide, and thefirst side of the waveguide is configured to face the user.
 15. Theoptical stack of claim 14, wherein presenting image light to the usercomprises presenting the image light via total internal reflection ofthe waveguide.
 16. The optical stack of claim 14, further comprising aphotochromic layer configured to adjust an amount of scene lightpresented to the user based on an intensity level of the scene light.17. The optical stack of claim 16, wherein the second protective layercomprises the photochromic layer.
 18. The optical stack of claim 16,wherein the photochromic layer is disposed on a first side of the secondprotective layer, the first side of the second protective layer facingthe user.
 19. The optical stack of claim 16, wherein the photochromiclayer is disposed on a second side of the second protective layer, thesecond side of the second protective layer opposite the user.
 20. Theoptical stack of claim 14, wherein the electrochromic layer isconfigured to configured to adjust an amount of scene light presented tothe user based on a control signal.
 21. The optical stack of claim 20,wherein the control signal is provided by one or more processors of awearable head device.
 22. The optical stack of claim 1, wherein theoptical stack is coupled to a wearable head device.